tag me if you get the answer you like.
MY suggestion is start raw. Get Audacity. Work with sound files
directly. You have unlimited tracks. With youtube downloading
add-ons, you can use any song.
There's no complication. It's flat like streams of cassette
tapes yet extremely flexible. Copy paste, copy paste, copy
paste, and you can accomplish anything the fancy programs do.
Plus, it's a great utility for sound. I live in audiacity,
especially when making things for Vine or Youtube videos.
But something that does instruments? I dunno. That's harder. I'm
still looking for one for myself that not a pain in the ass or
money. If she's *willing* to learn FL, then go for it. On Vine,
there's 10-11 yr old DJs that are mixing together their own
songs using FL [because there's really not much other choice out
there at present] - and you wouldn't *know* they're 10-11 unless
they do a face reveal. Personally, I think that's awesome
because age doesn't matter when you have skills.